Reflector-shade for lamps.



` 11. B. BENJAMIN. 'REFLEcToR 'SHADE Foa LAMPS,- f APPLICATION FILEDUOCT. l0, 1933.

Patented June 6, 1916.

y 3 SHEETS-SHEET 'I- R. B. BENJAMIN.

REFLECTOR SHADE FOR LAMPS.

APPLICATION FILED ocr. 10. 1913.

l ,1 86,1 65 Patented June 6, 1916.

3 SHEETS-SHEET 2.

R. B. BENJAMIN.

REFLECTOR SHADE FOR LAMPS.

APPLICATION FILED 0421.10, 1913.

Patented J une 6, 1916.

3 SHEETS-SHEET 3.

UNITED STATES PATENT oEEioE.

REUBEN B. BENJAMIN, OF CHICAGO, ILLINOIS, ASS'IGNOR T0 BENJAMIN ELECTRIC l MANUFACTURING COMPANY, 0F CHICAGO, ILLINOIS, ACORPORATION OF ILLINOIS. i

vREELEGT'Dlt-SHADE FOR LAMPS.

Specification of Letters Patent.

Application led VOctober 10, 1913. Serial No. 794,489.

Reflector shades, and especially bowl shades, as heretofore known, have been subject to the disadvantage that a large percentage of the light rays emanating from the lamp filament are reflected back along paths that pass through the lamp bulb. In thus passing through two thicknesses of glass, much of the 'reflected light is absorbed, the eiciency of the shadebeing thus lessened. The loss is particularly noticeable in the case of bowl-frosted lamp bulbs.

It is the principal object of my invention to obviate this disadvantage, and to provide a reflector shade of a higher eliciency than has heretofore been produced. This object is attained by forming portions of the rellecting surface of the shade in such a manner that the light rays incident thereon will be reflected out through the space which exists between the lamp bulb and the inner surface of the shade. i

A reflector shade embodying my invention is described, by way of example, in .the following specification, and shown in lthe accompanying drawings, in which:

Figure 1 is a vertical section through the reflector shade, a lamp socket and lamp being shown in position therein; Figs. 2-8 are fragmentary sectional views, showing the arrangement of the radial corrugations of the shade, the sections being taken, respectively, on the lines 02--08 of Fig. 1; Fig. 9

is a view similar to a portion of Fig. 1, illustrating the manner in which the rays are reflected vertically; Figs. 10 and 11 are sectional views taken, respectively, on the lines 10-10 and 11-11 of Fig. 9, looking in the direction of the arrows, and illustrating the manner in which the rays indicated in Fig.

9 are'reflected laterally; and Fig. 12 is a horizontal section taken on the line 12-12 in Rellector- Shades for of Fig. 1, looking in the direction of the arrows.

The reflector shade embodying my invention now to be described, has a bowl portion 13 and a casing portion 14, the latter being adapted to inclose and contain the lamp socket 15 and the reduced upper end of the lamp16. In the top of the casing portion Patented J une 6, 1916. Y

14 is an aperture in which is arranged a bushing 17 adapted to receive a conduit or the like. l. The lower end of the bushing 17 is screw-threaded onthe exterior to engage the interior screw-threads ofl astirrup 18 which is disposed within the casing 14 and secured to the socket 15 -by screws 19. Between the casing portion 14 and the bushing 17 and the flange 20 and stirrup 18, respectively, are placedy a pair of washers 22 and 23. In the casing 14 just` above the bowl portion are a plurality of Ventilating apertures 25.

The bowl portion 13 of the shade is luted or corrugated, the corrugations 26 having the form and angularity shown in the drawings by Figs. 1-8. These corrugations 26 are radial and as the shade widens out the cor` rugations uniformly diminish. lThat is, at a point near the top of the shade the degree of corrugation is greatest, and near the bottom of the shade the corrugations mergeinto a spherical surface. To be more specific, reference is made to Figs. 2-8 taken in connection with Fig. 1. Considering the point A (Fig. 1) as a center, it will be seen that 'A at a point 30 removed from the axis of the shade, that is, almost at the top of the'bowl, the shade is plain and unfluted, (Fig. 2). At a point 40 removed the.corrugation in the shade has an angle of 125 (Fig. 3) and at the 60 point the angle is 136 (Fig. 4). Continuing in this manner it will be apparent fromthe'figures of the drawings above referred to, that the angle of the corrugations increases, uniformly toward the bottom of the shade until at a point from the axis, the corrugations lmerge into a spherical surface (Fig. 8). At its lower part, the bowl portion 13 is formed with a flaring hood portion 24.

The result of forming the shade as described above is that the great majority -of the reflected rays are projected downwardly and outwardly through the space between the shade and the lamp bulb; so that there is little impairment of efficiency due to loss of light b y absorption in passing through the lamp bulb. It has been noted that asthe bowl portion 13 widensy out the degree of corrugation diminishes, so that the above ef# fect obtains throughout the entire depth of the bowl portion. Figs. 9-11 showv this clearly, the two rays there shown being taken at random as examples. For the purposes of description, it is assumed that the light rays emanate from a single point A, at the center of the ilament. Considering Fig. 9, which shows the vertical paths traversed by the rays, AD represents a ray strik ing the shade at the point D, and DF represents the corresponding reflected ray. AE represents another ray incident at E and refiected along EG.

Fig. -9 shows the paths of the rays AD, DF and AE, EG, considered vertically. Figs. 10 and 1I show the same rays considered laterally, the sections on which these figures are taken being on the same planes as the rays DF and EG, respectively. That is, Fig. 9 shows the rays projected downwardly and Figs. l0 and ll illustrate the paths along which the rays are reiected outwardly, the latter figures clearly showing that such paths pass through the space`between the shade and the side of the lamp. It is seen, therefore, that by virtue of the corrugations and their arrangement, the angle of incidence of substantially every ray striking the shade is such that the corresponding reiiected ray passes downwardly and outwardly through the space existing between the shade and the lamp. 'Loss by absorption, due to the passage of rays through the lamp bulb, is thus avoided.

Not only does my invention make possible a shade of greater eiiiciency than heretofore known, by doing away with loss due to absorption, but in addition a shade so constructed possesses ornamental features, and, furthermore, the corrugations provide an additional element of strength in the shade.

Having thus described my. invention, what I claim as new and desire to secure by Letters Patent is;

1. A bowl shaped reiector shade comprising angularly disposed portions each curving downwardly and gradually enlarging so as to project the rays incident thereon downwardly and sidewise to avoid the bulb and shade. v

2. A bowl shaped reflector shade for lamps comprising radial corrugations with angularly disposed sides whose angular relations gradually increase so as to merge into a substantially circular surface at the lower end of the shade, said sides also curving vertically' so as 4to project the rays of light incident thereon downwardly and side- Wise between the Ibulb and shade.

3. A reflector shade for lamps having a portion of its surface substantially perpendicular to a line bisecting the angle between a line from the source of light to a point in said surface, and a line from said point extending between the side of the lamp andthe shade, and also extending outside of the plane through said point and the axis of the lamp.

4. A refiector shade for lamps having a bowl shaped radially corrugated surface having portions each of which is substantially perpendicular to a line bisecting the angle between a line from the source of light to a point in said surface, and a line from said point extending between the side of the lamp and the shade, and also extending outside of the plane through said point and the axis of the lamp. Y

5. A reector shade for lamps having a bowl shaped radially corrugated surface having portions each of which is substantially perpendicular to a line bisecting the angle between a line from the source of light to a point in said surface, and a line from said point extending between the side of the lamp and the shade, and also extending outside of the plane through said point and the Y axis of the lamp, the acuteness of the angle between the sides of said corrugations decreasing outwardly.

In witness whereof, I have hereunto subscribed my name in the presence of two witnesses.

- REUBEN B. BENJAMIN. Witnesses:

E. R. KING, W. PERRY HAHN. 

